Ben Glover, of in­de­pen­dent think-tank Demos, which com­piled the re­port, said: “Un­paid car­ers have for decades been taken for granted by pol­icy mak­ers.”

He­len Walker, of Car­ers UK, said: “The amount of care pro­vided by fam­i­lies is on the rise yet the amount of ser­vices from lo­cal coun­cils is fall­ing.” The char­ity wants car­ers given the right to paid care leave, and more fund­ing for car­ers’ breaks.

There were 5.8 mil­lion car­ers in 2001, ris­ing to 6.5 mil­lion by 2011 then soar­ing to 8 mil­lion by 2018 – up 35% on 2001, the re­port said. The Lo­cal Gov­ern­ment As­so­ci­a­tion es­ti­mates coun­cils face a fund­ing black hole of al­most £8bil­lion by 2025.

Demos is call­ing for the Carer’s Al­lowance to be raised at least to the same level as Job­seeker’s Al­lowance, and for two mil­lion more to be­come el­i­gi­ble. It would cost £10.2bil­lion funded by a 1% Na­tional In­sur­ance rise. A Gov­ern­ment spokes­woman said: “Since 2010 we’ve in­creased Carer’s Al­lowance. Car­ers may also be el­i­gi­ble for higher rates of other ben­e­fits.”